AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-14 23:26:39 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge branch 'tcp-in-slow-start'

Browse Source 
Yuchung Cheng says:

====================
tcp: fixes some congestion control corner cases

This patch series fixes corner cases of TCP congestion control.
First issue is to avoid continuing slow start when cwnd reaches ssthresh.
Second issue is incorrectly processing order of congestion state and
cwnd update when entering fast recovery or undoing cwnd.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-07-09 14:22:53 -07:00
commit 986ca37eae
14 changed files with 26 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/net/tcp.h
View File

@ -989,6 +989,11 @@ static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
#define TCP_INFINITE_SSTHRESH 0x7fffffff
static inline bool tcp_in_slow_start(const struct tcp_sock *tp)
{
return tp->snd_cwnd < tp->snd_ssthresh;
}
static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp)
{
return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH;
@ -1065,7 +1070,7 @@ static inline bool tcp_is_cwnd_limited(const struct sock *sk)
const struct tcp_sock *tp = tcp_sk(sk);
/* If in slow start, ensure cwnd grows to twice what was ACKed. */
if (tp->snd_cwnd <= tp->snd_ssthresh)
if (tcp_in_slow_start(tp))
return tp->snd_cwnd < 2 * tp->max_packets_out;
return tp->is_cwnd_limited;

2
net/ipv4/tcp_bic.c
View File

@ -146,7 +146,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (!tcp_is_cwnd_limited(sk))
return;
if (tp->snd_cwnd <= tp->snd_ssthresh)
if (tcp_in_slow_start(tp))
tcp_slow_start(tp, acked);
else {
bictcp_update(ca, tp->snd_cwnd);

2
net/ipv4/tcp_cdg.c
View File

@ -264,7 +264,7 @@ static void tcp_cdg_cong_avoid(struct sock *sk, u32 ack, u32 acked)
u32 prior_snd_cwnd;
u32 incr;
if (tp->snd_cwnd < tp->snd_ssthresh && hystart_detect)
if (tcp_in_slow_start(tp) && hystart_detect)
tcp_cdg_hystart_update(sk);
if (after(ack, ca->rtt_seq) && ca->rtt.v64) {

6
net/ipv4/tcp_cong.c
View File

@ -365,10 +365,8 @@ int tcp_set_congestion_control(struct sock *sk, const char *name)
*/
u32 tcp_slow_start(struct tcp_sock *tp, u32 acked)
{
u32 cwnd = tp->snd_cwnd + acked;
u32 cwnd = min(tp->snd_cwnd + acked, tp->snd_ssthresh);
if (cwnd > tp->snd_ssthresh)
cwnd = tp->snd_ssthresh + 1;
acked -= cwnd - tp->snd_cwnd;
tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp);
@ -413,7 +411,7 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked)
return;
/* In "safe" area, increase. */
if (tp->snd_cwnd <= tp->snd_ssthresh) {
if (tcp_in_slow_start(tp)) {
acked = tcp_slow_start(tp, acked);
if (!acked)
return;

4
net/ipv4/tcp_cubic.c
View File

@ -320,7 +320,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (!tcp_is_cwnd_limited(sk))
return;
if (tp->snd_cwnd <= tp->snd_ssthresh) {
if (tcp_in_slow_start(tp)) {
if (hystart && after(ack, ca->end_seq))
bictcp_hystart_reset(sk);
acked = tcp_slow_start(tp, acked);
@ -439,7 +439,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
ca->delay_min = delay;
/* hystart triggers when cwnd is larger than some threshold */
if (hystart && tp->snd_cwnd <= tp->snd_ssthresh &&
if (hystart && tcp_in_slow_start(tp) &&
tp->snd_cwnd >= hystart_low_window)
hystart_update(sk, delay);
}

2
net/ipv4/tcp_highspeed.c
View File

@ -116,7 +116,7 @@ static void hstcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (!tcp_is_cwnd_limited(sk))
return;
if (tp->snd_cwnd <= tp->snd_ssthresh)
if (tcp_in_slow_start(tp))
tcp_slow_start(tp, acked);
else {
/* Update AIMD parameters.

2
net/ipv4/tcp_htcp.c
View File

@ -236,7 +236,7 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (!tcp_is_cwnd_limited(sk))
return;
if (tp->snd_cwnd <= tp->snd_ssthresh)
if (tcp_in_slow_start(tp))
tcp_slow_start(tp, acked);
else {
/* In dangerous area, increase slowly.

2
net/ipv4/tcp_hybla.c
View File

@ -112,7 +112,7 @@ static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 acked)
rho_fractions = ca->rho_3ls - (ca->rho << 3);
if (tp->snd_cwnd < tp->snd_ssthresh) {
if (tcp_in_slow_start(tp)) {
/*
* slow start
* INC = 2^RHO - 1

2
net/ipv4/tcp_illinois.c
View File

@ -268,7 +268,7 @@ static void tcp_illinois_cong_avoid(struct sock *sk, u32 ack, u32 acked)
return;
/* In slow start */
if (tp->snd_cwnd <= tp->snd_ssthresh)
if (tcp_in_slow_start(tp))
tcp_slow_start(tp, acked);
else {

8
net/ipv4/tcp_input.c
View File

@ -3568,10 +3568,6 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
&sack_state);
acked -= tp->packets_out;
/* Advance cwnd if state allows */
if (tcp_may_raise_cwnd(sk, flag))
tcp_cong_avoid(sk, ack, acked);
if (tcp_ack_is_dubious(sk, flag)) {
is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP));
tcp_fastretrans_alert(sk, acked, prior_unsacked,
@ -3580,6 +3576,10 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
if (tp->tlp_high_seq)
tcp_process_tlp_ack(sk, ack, flag);
/* Advance cwnd if state allows */
if (tcp_may_raise_cwnd(sk, flag))
tcp_cong_avoid(sk, ack, acked);
if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) {
struct dst_entry *dst = __sk_dst_get(sk);
if (dst)

2
net/ipv4/tcp_metrics.c
View File

@ -461,7 +461,7 @@ void tcp_update_metrics(struct sock *sk)
tcp_metric_set(tm, TCP_METRIC_CWND,
tp->snd_cwnd);
}
} else if (tp->snd_cwnd > tp->snd_ssthresh &&
} else if (!tcp_in_slow_start(tp) &&
icsk->icsk_ca_state == TCP_CA_Open) {
/* Cong. avoidance phase, cwnd is reliable. */
if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))

2
net/ipv4/tcp_scalable.c
View File

@ -22,7 +22,7 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (!tcp_is_cwnd_limited(sk))
return;
if (tp->snd_cwnd <= tp->snd_ssthresh)
if (tcp_in_slow_start(tp))
tcp_slow_start(tp, acked);
else
tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT),

6
net/ipv4/tcp_vegas.c
View File

@ -225,7 +225,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 acked)
*/
diff = tp->snd_cwnd * (rtt-vegas->baseRTT) / vegas->baseRTT;
if (diff > gamma && tp->snd_cwnd <= tp->snd_ssthresh) {
if (diff > gamma && tcp_in_slow_start(tp)) {
/* Going too fast. Time to slow down
* and switch to congestion avoidance.
*/
@ -240,7 +240,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 acked)
tp->snd_cwnd = min(tp->snd_cwnd, (u32)target_cwnd+1);
tp->snd_ssthresh = tcp_vegas_ssthresh(tp);
} else if (tp->snd_cwnd <= tp->snd_ssthresh) {
} else if (tcp_in_slow_start(tp)) {
/* Slow start. */
tcp_slow_start(tp, acked);
} else {
@ -281,7 +281,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 acked)
vegas->minRTT = 0x7fffffff;
}
/* Use normal slow start */
else if (tp->snd_cwnd <= tp->snd_ssthresh)
else if (tcp_in_slow_start(tp))
tcp_slow_start(tp, acked);
}

2
net/ipv4/tcp_veno.c
View File

@ -150,7 +150,7 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 acked)
veno->diff = (tp->snd_cwnd << V_PARAM_SHIFT) - target_cwnd;
if (tp->snd_cwnd <= tp->snd_ssthresh) {
if (tcp_in_slow_start(tp)) {
/* Slow start. */
tcp_slow_start(tp, acked);
} else {